1. Field of the Invention
The present invention is broadly concerned with an improved system and method for patching of damaged roadways by filling "potholes" or other concave damaged regions with an improved fill having water barrier and longevity properties exceeding present day patching systems. More particularly, the invention pertains to such patches wherein a lower asphaltic liner is placed in the damaged region of a roadway in closely conforming relationship to the inner contour thereof followed by asphaltic fill material and a final asphaltic upper top mat covering the fill material and extending substantially over the damaged region to engage adjacent roadway portions.
2. Description of the Prior Art
The repair of "potholes" or other damaged areas in roadways has presented a continuing problem for municipal and highway engineers. Once a pothole is formed, it will continue to expand and erode under vehicular traffic and ambient temperature conditions. Therefore, a patch or repair is essential to prevent virtual destruction of the roadway.
The traditional approach in repairing potholes has been to fill the pothole with an asphaltic patching material. Generally, these repairs are done by road crews who simply fill and pack the pothole with the asphaltic repair material, forming a crown of the patching material. These types of repairs are generally unsatisfactory, and have relatively short services lives, especially on heavily traveled roadways. A prime deficiency with such patching efforts stems from the fact that moisture can readily migrate from the roadway into the patching material, which tends to degrade the patch particularly in cold weather conditions where the patch is subjected to freeze-thaw cycles. Also, normal rainfall will also cause moisture to be taken up by the patching material.
U.S. Pat. No. 5,183,353 describes a pavement repair fill wherein a water-impervious sheet is laid over the fill material as a barrier. In order to attach the sheet, tar is applied over the fill and extended outwardly beyond the peripheral edges of the hole. It is believed that patches in accordance with the '353 patent are deficient in that no provision is made for a water-impervious liner beneath the fill material. As a consequence, the fill can still take up moisture from within the adjacent roadway.